Batrachoseps attenuatus (Eschscholtz,
1833) California Slender Salamander (Batrachoseps
attenuatus gallery)
Slender Salamanders are found exclusively in
western United States, particularly in the state of California. Only one
of the 19 recognized species does not appear in California, Batrachoseps
wrighti, which is found in the northern state of Oregon. Slender
salamanders vary in appearance and environmental preference, but all are
characterized by obvious costal and caudal grooves, rather minute limbs,
four digits on each foot, and elongate forms (to varying degrees). The
more slender species are sometimes referred to as "worm
salamanders", also applied to the genus Oedipina, a
reflection of their long, slender appearance, accompanied by tiny
limbs...Introduction
California Slender Salamanders are very common throughout their range,
often showing up in residential gardens and yards. These tiny, worm-like
salamanders prefer to remain hidden under rotting logs, leaf litter, and
virtually any other cover that maintains moist substrate. California
Slender Salamanders are especially active during their breeding season,
fall and winter, and remain underground during the warmer months.
Identification of B. attenuatus
1.25 - 2.00 inches from snout to vent (SV), with a tail that may be 1.5 to 2
times the length of the body. 18-21 costal grooves, and 10-12 folds between
adpressed limbs (Stebbins, 2003). B. attenuatus are one of the more
"worm-like" slender salamanders, with minute limbs, and a narrow head.
The dorsum may be reddish, orange, dark gray, or pale orange colored, sometimes
with a dorsal stripe. When in the typical coiled defense posture, the dorsal
stripe may aid in mimicking distasteful millipedes in some populations. The
belly may be light to dark grayish, with or without a blue tinge, and spotted
with cream colored dots. The underside of the tail is usually lighter than the
belly color. Northern California populations typically possess reddish or rusty
colored dorsa, especially those found in redwood forests. Populations around
the San Francisco Bay display a variety of dorsal colors. Males can be
differentiated from females by their blunt, square-shaped snouts, and the
presence of premaxillary teeth that extend just beyond the edge of a closed
mouth (Stebbins, 2003).
Distribution & Natural Habitat
B. attenuatus are common in northwestern and central California. The
range extends from extreme southwestern Oregon, southward, along the coast to
San Benito Co. Populations are also found in the Sierra Nevada foothills from
Chico to Calaveras Co., Sutter Buttes area, and Shasta Co. (Stebbins, 2003).
This species inhabits a variety of environments, including oak groves,
grasslands, chaparral, woodland areas, and residential gardens.
Within their range, B. attenuatus are often found in residential
areas, hiding under objects that retain substrate moisture. Those living
with the range may find B. attenuatus are common sight around their
yards, especially during the fall and winter.
Breeding
Breeding males develop broader snouts than females, and enlarged
premaxillary teeth that extend beyond the lip.
Breeding begins
in fall, usually during the first rains. However, males have been observed
possessing viable sperm in the summer months, indicating that underground
breeding may occur at this time. Slender salamanders attach
several eggs to the roofs of hidden nests, such as the interior of rotting logs,
underground burrows, rock piles, and even in thick leaf litter. Egg nests tend
to be communal.
Eggs are deposited throughout fall and
winter, and young emerge in late winter and spring.
Defensive Habits
B. attenuatus sometimes possess colored dorsal stripes, which may
aid in mimicry of unpalatable millipedes in some populations. When
disturbed, B. attenuatus will first coil tightly and remain
immobile. Further provocation may result in the salamander writhing
around, bouncing back and forth, and possibly autotomizing the tail.
Regeneration of the tail will occur within 1-3 years of detachment. In
their natural habitat, B. attenuatus are preyed upon by sympatric Aneides
flavipunctatus, and other small predators.
Photo © Gary Nafis,
California Reptiles and Amphibians
more photos of
Batrachoseps
attenuatus
References
Petranka, James W. Salamanders of the United States and Canada. Smithsonian Institution Press, 1998.
Stebbins, Robert C. Western Reptiles and Amphibians (third edition). Houghton Mifflin Company, 2003.
ARMI National Atlas for Amphibian Distributions (Database). United
States Geological Survey.
http://www.mp2-pwrc.usgs.gov/armiatlas
(Accessed: 2003).
Nature Serve Explorer (Database). Nature Serve.
http://www.natureserve.org/explorer/index.htm
(Accessed: 2003).
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